Fragaria x ananassa
The small flowers of strawberries have 5 sepals, 5 petals, a very short hypanthium, many stamens, and an apocarpous gynoecium of many free carpels on an elevated receptacle. This set of slides shows the development of strawberry fruits. In the longitudinal section of a flower, right, there are many carpels on a small, cone-like receptacle. The photos in the lower left shows how this receptacle becomes fleshy as the fruit develops, and the carpels mature into achenes. The blue arrow in the lower right photo points to an achene with its persistent style. The ripe fruit of a strawberry comes from one flower and is thus an accessory, aggregate fruit of achenes. The cultivated strawberry, Fragaria x ananassa is of hybrid origin between two species, Fragaria virginiana of eastern North America and Fragaria chiloensis, which is native from Alaska to South America. Both parent species and the hybrid are octoploids, that is they have 8 sets of chromosomes.
NOTE: You may need to make your viewing wider in order to see two images side by side on the monitor screen.
- - 
- - 
Return to Ken Robertson's homepage